Ecdysone receptors and methods for their use

Abstract

The field of the invention is inducible gene expression systems wherein expression is controlled by a novel ecdysone or ultraspiracle receptor or its derivatives. The field particularly relates to the isolation and characterization of nucleic acid and polypeptides for a novel ecdysone receptor and a novel ultraspiracle receptor. The nucleic acid and polypeptides are useful in novel gene expression systems inducible with ecdysone or derivative receptor agonists.

1. A method of selectively inducing expression of a nucleotide sequence of interest in a plant, said method comprising:
 a) stably incorporating into the genome of said plant a first expression cassette, said first expression cassette comprising a first promoter operably linked to a first nucleotide sequence that encodes a first protein having ecdysone receptor activity, wherein said first nucleotide sequence has at least 90% sequence identity to the coding sequence set forth in nucleotides 368–2005 of SEQ ID NO: 1; 
 b) stably incorporating into the genome of said plant a second expression cassette, wherein said second expression cassette comprises a transcriptional regulatory region operably linked to a second nucleotide sequence which is designated the target sequence; 
 c) stably incorporating into the genome of said plant a third expression cassette comprising a promoter operably linked to a third nucleotide sequence that encodes a second protein having ultraspiracle activity, wherein said third nucleotide sequence has at least 90% sequence identity to the coding sequence set forth in nucleotides 224–1603 of SEQ ID NO: 3; and 
 d) contacting said plant with a ligand that binds to at least one of said proteins to form a ligand-protein complex, wherein said ligand-protein complex interacts with said transcriptional regulatory region to induce expression of said target sequence. 
 
     
     
       2. The method of  claim 1 , wherein said first nucleotide sequence has at least 95% sequence identity to the coding sequence set forth in nucleotides 368–2005 of SEQ ID NO: 1. 
     
     
       3. The method of  claim 1 , wherein said third nucleotide sequence has at least 95% sequence identity to the coding sequence set forth in nucleotides 224–1603 of SEQ ID NO: 3. 
     
     
       4. The method of  claim 1 , wherein said plant is a dicot. 
     
     
       5. The method of  claim 1 , wherein said plant is a monocot. 
     
     
       6. The method of  claim 5 , wherein said monocot is maize. 
     
     
       7. The method of  claim 1 , wherein said ligand-protein complex comprises heterodimers of said first protein and said second protein. 
     
     
       8. A plant having stably incorporated in its genome:
 a) a first expression cassette comprising a first promoter operably linked to a first nucleotide sequence that encodes a first protein having ecdysone receptor activity, wherein said first nucleotide sequence has at least 90% sequence identity to the coding sequence set forth in nucleotides 368–2005 of SEQ ID NO: 1; 
 b) a second expression cassette comprising a transcriptional regulatory region operably linked to a second nucleotide sequence which is designated the target sequence, wherein said transcriptional regulatory region is activated by a ligand-protein complex; and 
 c) a third expression cassette comprising a promoter operably linked to a third nucleotide sequence that encodes a second protein having ultraspiracle activity, wherein said third nucleotide sequence has at least 90% sequence identity to the coding sequence set forth in nucleotides 224–1603 of SEQ ID NO: 3. 
 
     
     
       9. The plant of  claim 8 , wherein said first nucleotide sequence has at least 95% sequence identity to the coding sequence set forth in nucleotides 368–2005 of SEQ ID NO: 1. 
     
     
       10. The plant of  claim 8 , wherein said third nucleotide sequence has at least 95% sequence identity to the coding sequence set forth in nucleotides 224–1603 of SEQ ID NO: 3. 
     
     
       11. Transformed seed of the plant of  claim 8 , wherein said seed has stably incorporated in its genome at least one of said first expression cassette, or said third expression cassette. 
     
     
       12. A plant cell having stably incorporated in its genome:
 a) a first expression cassette comprising a first promoter operably linked to a first nucleotide sequence that encodes a first protein having ecdysone receptor activity, wherein the nucleotide sequence encoding said first protein having ecdysone receptor activity is set forth in SEQ ID NO: 1; 
 b) a second expression cassette comprising a transcriptional regulatory region operably linked to a target sequence, wherein said transcriptional regulatory region is activated by a ligand-protein complex; and 
 c) a third expression cassette comprising a promoter operably linked to a third nucleotide sequence that encodes a second protein having ultraspiracle activity, wherein the nucleotide sequence encoding said second protein having ultraspiracle activity is set forth in SEQ ID NO: 3. 
 
     
     
       13. A plant cell having stably incorporated in its genome:
 a) a first expression cassette comprising a first promoter operably linked to a first nucleotide sequence that encodes a protein having ecdysone receptor activity, wherein said first nucleotide sequence has at least 90% sequence identity to the coding sequence set forth in nucleotides 368–2005 of SEQ ID NO: 1; 
 b) a second expression cassette comprising a transcriptional regulatory region operably linked to a target sequence, wherein said transcriptional regulatory region is activated by a ligand-protein complex; and 
 c) a third expression cassette comprising a second promoter operably linked to a third nucleotide sequence that encodes a protein having ultraspiracle activity, wherein said third nucleotide sequence has at least 90% sequence identity to the coding sequence set forth in nucleotides 224–1603 of SEQ ID NO: 3. 
 
     
     
       14. The plant cell of  claim 13 , wherein said first nucleotide sequence has at least 95% sequence identity to the coding sequence set forth in nucleotides 368–2005 of SEQ ID NO: l. 
     
     
       15. The plant cell of  claim 13 , wherein said third nucleotide sequence has at least 95% sequence identity to the coding sequence set forth in nucleotides 224–1603 of SEQ ID NO: 3. 
     
     
       16. The plant cell of  claim 13 , wherein said plant cell is a monocot plant cell. 
     
     
       17. The plant cell of  claim 13 , wherein at least one of said first promoter or said second promoter is a tissue-preferred promoter. 
     
     
       18. The plant cell of  claim 13 , wherein expression of said target sequence disrupts plant fertility.